Pitcher's box in SP

[Andy]

For those of you that work slowpitch, either leagues or tournaments, are you finding the use of the "pitcher's box" becoming more common?

I'm talking about a defined area around the pitcher's plate, usually marked, that the pitcher must start the pitch from. If a ball is hit through this area, it results in some sort of warning and/or penalty to the offensive team.

I am involved with two seperate city SP leagues, in one league, if the ball is hit through the box on the fly within reach of the pitcher, the first occurrance is a warning to both teams, any occurrance after that is an out. The rule only applies if the pitcher is in the box when the ball passes through.

In the other league, any ball hit through the box within reach of the pitcher is an out, whether the pitcher is in the box or not.

I know that this is not part of ASA rules, is it part of any other asscoiation? Is there any talk of introducing some form of the box as a rule change in ASA? If it's used in your neighborhoods, how is the rule worded and enforced?